// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/threading/platform_thread.h"

#include <errno.h>
#include <stddef.h>
#include <sys/prctl.h>
#include <sys/resource.h>
#include <sys/types.h>
#include <unistd.h>

#include "base/android/jni_android.h"
#include "base/android/thread_utils.h"
#include "base/lazy_instance.h"
#include "base/logging.h"
#include "base/threading/platform_thread_internal_posix.h"
#include "base/threading/thread_id_name_manager.h"
#include "base/tracked_objects.h"
#include "jni/ThreadUtils_jni.h"

namespace base {

namespace internal {

    // - BACKGROUND corresponds to Android's PRIORITY_BACKGROUND = 10 value and can
    // result in heavy throttling and force the thread onto a little core on
    // big.LITTLE devices.
    // - DISPLAY corresponds to Android's PRIORITY_DISPLAY = -4 value.
    // - REALTIME_AUDIO corresponds to Android's PRIORITY_AUDIO = -16 value.
    const ThreadPriorityToNiceValuePair kThreadPriorityToNiceValueMap[4] = {
        { ThreadPriority::BACKGROUND, 10 },
        { ThreadPriority::NORMAL, 0 },
        { ThreadPriority::DISPLAY, -4 },
        { ThreadPriority::REALTIME_AUDIO, -16 },
    };

    bool SetCurrentThreadPriorityForPlatform(ThreadPriority priority)
    {
        // On Android, we set the Audio priority through JNI as Audio priority
        // will also allow the process to run while it is backgrounded.
        if (priority == ThreadPriority::REALTIME_AUDIO) {
            JNIEnv* env = base::android::AttachCurrentThread();
            Java_ThreadUtils_setThreadPriorityAudio(env, PlatformThread::CurrentId());
            return true;
        }
        return false;
    }

    bool GetCurrentThreadPriorityForPlatform(ThreadPriority* priority)
    {
        DCHECK(priority);
        *priority = ThreadPriority::NORMAL;
        JNIEnv* env = base::android::AttachCurrentThread();
        if (Java_ThreadUtils_isThreadPriorityAudio(
                env, PlatformThread::CurrentId())) {
            *priority = ThreadPriority::REALTIME_AUDIO;
            return true;
        }
        return false;
    }

} // namespace internal

void PlatformThread::SetName(const std::string& name)
{
    ThreadIdNameManager::GetInstance()->SetName(CurrentId(), name);
    tracked_objects::ThreadData::InitializeThreadContext(name);

    // Like linux, on android we can get the thread names to show up in the
    // debugger by setting the process name for the LWP.
    // We don't want to do this for the main thread because that would rename
    // the process, causing tools like killall to stop working.
    if (PlatformThread::CurrentId() == getpid())
        return;

    // Set the name for the LWP (which gets truncated to 15 characters).
    int err = prctl(PR_SET_NAME, name.c_str());
    if (err < 0 && errno != EPERM)
        DPLOG(ERROR) << "prctl(PR_SET_NAME)";
}

void InitThreading()
{
}

void TerminateOnThread()
{
    base::android::DetachFromVM();
}

size_t GetDefaultThreadStackSize(const pthread_attr_t& attributes)
{
#if !defined(ADDRESS_SANITIZER)
    return 0;
#else
    // AddressSanitizer bloats the stack approximately 2x. Default stack size of
    // 1Mb is not enough for some tests (see http://crbug.com/263749 for example).
    return 2 * (1 << 20); // 2Mb
#endif
}

bool RegisterThreadUtils(JNIEnv* env)
{
    return RegisterNativesImpl(env);
}

} // namespace base
